class Solution {
public:
    int climbStairs(int n) {
        int dp[100];
        dp[1] = 1;
        dp[2] = 2;
        for (int i = 3; i <= n; i++)
        {
            dp[i] = dp[i - 2] + dp[i - 1];
        }
        return dp[n];
    }
};